The invention relates to a metal gasket to be disposed between, for example, a cylinder block and a cylinder head of an internal combustion engine.
In a metal gasket 100 disclosed in Japanese Patent Publication (KOKAI) No. 11-230355, as shown in FIG. 7, a gasket base plate 101 is provided with a plurality of annular beads 102 and 103 around a cylinder bore. When a cylinder head 104 and a cylinder block 105 are tightened, high surface pressures are generated at abutting portions between the cylinder head 104 and the annular bead 102 and between the cylinder block 105 and the annular beads 103 to improve the sealing ability thereat.
However, in the metal gasket 100, a high surface pressure is generated at the abutting portion where the annular bead 102 or 103 abuts against the cylinder head 104 or the cylinder block 105, and forms a pressure trace at the abutting surface. When the tightening of the cylinder head 104 and the cylinder block 105 is released for repair or inspection and the cylinder head 104 and the cylinder block 105 are tightened again with a new gasket 100 therebetween, the pressure trace does not necessarily match the annular bead 102 of the new metal gasket 100. Therefore, there has been a problem that the sealing ability at the tightening portion is lowered.
In view of the above problems, the present invention has been made, and an object of the invention is to provide a metal gasket wherein a plurality of annular beads increases surface pressures at abutting portions, and a pressure trace is not formed on an abutting surface of the cylinder head.
Further objects and advantages of the invention will be apparent from the following description of the invention.